噻苯隆-乙烯利复配对春玉米籽粒灌浆特性的影响及其激素调控机理

Effects of mixture of thidiazuron and ethephon on grain-filling characteristics and hormone regulation mechanism in spring maize

以"先玉335"和"鑫鑫2号"为试验材料,于花后25 d喷施噻苯隆和噻苯隆-乙烯利复配剂,清水为对照,探究噻苯隆-乙烯利复配对玉米籽粒灌浆后期灌浆特性的影响及其激素调控机理。结果表明:噻苯隆-乙烯利复配可以缩短籽粒灌浆快增期和缓增期的灌浆持续时间,提高灌浆平均速率和籽粒重量,显著增加春玉米灌浆后期籽粒中生长素(IAA)和赤霉素(GA)含量,降低脱落酸(ABA)和细胞分裂素(CTK)含量;同时显著提高灌浆期籽粒IAA与ABA、GA与ABA比例,降低CTK与IAA、CTK与GA比例,对CTK与ABA、GA与IAA比例影响较小。相关分析表明,噻苯隆-乙烯利复配处理后,春玉米籽粒中ABA和CTK含量与灌浆快增期速率呈显著负相关。本研究表明,噻苯隆-乙烯利复配主要通过影响籽粒中IAA、ABA、CTK和GA含量及其比例,从而调控春玉米籽粒灌浆进程,最终实现春玉米产量提高,熟期提前的功效。研究为噻苯隆-乙烯利复配应用到玉米生产上提供理论及试验依据。

In order to explore the effect of the mixture of thidiazuron and ethephon on grainfilling characteristics and hormone changes in grains during late grain-filling stage of spring maize, two maize hybrids （‘Xianyu 335’ and ‘Xinxin 2’） were treated with thidiazuron and the mixture of thidiazuron and ethephon 25 days after anthesis, with water as control. The result showed that the mixture of thidiazuron and ethephon decreased the duration of rapid increase period and moderate increase period of grain-filling stage, increased the average filling rate and grain weight, significantly improved IAA （indole-3-acetic acid） and GA （gibberellin acid） contents in grains at late grain-filling stage, reduced the contents of ABA （abscisic acid） and CTK （cytokinin）. At the same time, the ratios of IAA/ABA and GA/ABA in grain-filling stage were significantly increased, and the ratios of CTK/IAA and CTK/GA were decreased, while the ratios of CTK/ABA and GA/IAA were less affected. After the treatment of thidiazuron and ethephon mixture, the contents of ABA and CTK in grains of spring maize were negatively correlated with the rate of rapid growth of grain filling. Our results indicated that the mixture of thidiazuron and ethephon regulated the grain-filling process of spring maize mainly through influencing IAA, ABA, CTK and GA contents and their proportions in grains, and ultimately advanced maturity and improved the yield of spring maize. This study will provide theoretical and experimental basis for application of the mixture of thidiazuron and ethephon to maize production.